Embodiments of the inventive concepts disclosed herein generally relate to the field of filters, and more particularly, but not by way of limitation, to filters including non-magnetic frequency selective limiters.
Radio frequency (RF) circuits are utilized in communication equipment, sensing equipment, and other applications. Generally, RF circuits often utilize limiters and filters. Frequency selective limiters (FSLs) are non-linear passive, two-port devices that can selectively attenuate undesired interference, thus improving the reception of desired signals. FSLs can be used in filters. An ideal FSL is capable of limiting the power of individual frequency components which are above a certain threshold level, without mutual interference or without affecting any other frequency components.
Conventional FSLs include ferrite or other magnetic material that attenuates signals above a predetermined threshold power level while passing signals below the threshold power level. The frequency selective nature of the magnetic material's high-power limiting characteristic is such that low power signals close in frequency to the limited signals are unaffected. FSLs including magnetic material have reduced design flexibility, are sensitive to temperature, are high cost, and are large in size and weight compared to printed circuit board components. Further, the magnetic materials often require permanent magnetic bias and are often limited to a fixed frequency range.